Flight start of engine groups 1 and 2 has what crank limit?

Flight start of engine groups 1 and 2 has what crank limit?

• A. 120 sec ON / 10 sec OFF
• B. 90 sec ON / 10 sec OFF
• C. 120 sec ON / 5 min OFF
• D. 90 sec ON / 5 min OFF

Answer: (A)

The crank limit is about protecting the starter and the engine during a start. For starting engine groups 1 and 2 in flight, you may crank for up to 120 seconds continuously. After that, you must pause for at least 10 seconds before attempting to crank again. This keeps the starter from overheating and gives the system a brief cooldown between start attempts. In practice, if the engine hasn’t ignited after 120 seconds of cranking, you stop, wait 10 seconds, then you can try again (or follow the applicable start procedure). The 10-second rest is the minimum cooldown, and the 120-second limit is the maximum continuous cranking time for a single start attempt. Longer rest periods (like several minutes) aren’t part of this start limit, and shorter 90-second limits aren’t aligned with the specified procedure for these engine groups.

The crank limit is about protecting the starter and the engine during a start. For starting engine groups 1 and 2 in flight, you may crank for up to 120 seconds continuously. After that, you must pause for at least 10 seconds before attempting to crank again. This keeps the starter from overheating and gives the system a brief cooldown between start attempts.

In practice, if the engine hasn’t ignited after 120 seconds of cranking, you stop, wait 10 seconds, then you can try again (or follow the applicable start procedure). The 10-second rest is the minimum cooldown, and the 120-second limit is the maximum continuous cranking time for a single start attempt.

Longer rest periods (like several minutes) aren’t part of this start limit, and shorter 90-second limits aren’t aligned with the specified procedure for these engine groups.